GeminiFocus January 2014 | Page 23

After finishing optical rework in April 2013 (Figure 2), F2 stepped closer to its final round of commissioning observations when it was moved from the Gemini South summit instrument lab onto port 5 of the Instrument Support Structure on June 11, 2013. The first preliminary science queue data were obtained July 19th, and regular queue observations began in late September. F2 began obtaining data in “shared-risk” mode in August 2013 and between then and mid-December has executed 15 queue programs. Despite this exciting milestone, challenges remained. One problem involved the instrument’s On-Instrument Wavefront Sensor (OIWFS) used to optimize the delivered image quality to the camera. During on-sky checks on the night of August 24th, an alignment problem with the OIWFS became apparent. An inspection quickly followed, and the mechanism was realigned as precisely as possible with minimum intrusion (i.e., without moving other optical components). PIs with programs in the 2013B queue were informed of the possibility of reverting to the use of PWFS2, and observations were prepared for either option, allowing queue observations to continue. An additional problem was discovered with repeatability of the Lyot wheel mechanism, but a solution was identified and the problem resolved in January2014 December. However, delivered image quality is a significant remaining issue, and is still under active investigation. These 2013B programs requested a total of 180 hours or 17 percent of the total available time on Gemini South, despite the fact that only imaging and the long-slit spectroscopy modes were offered in this first semester. Work is ongoing to offer the multi-object spectroscopy (MOS) mode later, after we gain more experience and time with the instrument. In parallel to the start of “shared-risk” science operations, and before the end of the 2013B semester, Gemini held an internal Operations Handover Review for F2. The review took a close look at the performance and operability of F2 in its present state with respect to the ultimate goal of successfully operating, maintaining, and supporting F2 as a facilityclass Gemini instrument, and delivering the expected scientific return to the Gemini community. The committee also assessed the remaining work going forward, including improving the GeminiFocus Figure 1. FLAMINGOS-2 nearinfrared commissioning image details part of the magnificent Swan Nebula (M17), where ultraviolet radiation streaming from young hot stars sculpts a dense region of dust and gas into myriad fanciful forms. M17 lies some 5,200 light-years distant in the constellation Sagittarius and is one of the most massive and luminous star-forming regions in our Galaxy. Field-of-view: 5.5 x 4.0 arcminutes. Credit: Gemini Observatory/AURA. Figure 2. Optical Engineer Constanza Araujo works on FLAMINGOS-2’s optical alignment and image quality testing prior to cool-down. 21